blob: ba8bc44c37a5e9b50ba7287609006145d4578a54 [file] [log] [blame]
Igor Sarkisovc9d10aa2020-10-06 15:22:51 -07001Hwclock is a program that runs under Linux and sets and queries the
2Hardware Clock, which is often called the Real Time Clock, RTC, or
3CMOS clock.
4
5Sometimes, you need to install hwclock setuid root. If you want users
6other than the superuser to be able to display the clock value using the
7direct ISA I/O method, install it setuid root. If you have the /dev/rtc
8interface on your system or are on a non-ISA system, there's probably
9no need for users to use the direct ISA I/O method, so don't bother.
10
11To install setuid root, do something like this:
12
13 chmod a=rx,u=s /sbin/hwclock
14
15In any case, hwclock will not allow you to set anything unless you have
16the superuser _real_ uid. (This is restriction is not necessary if you
17haven't installed setuid root, but it's there for now).
18
19You may want to preformat and/or compress the man page before installing.
20
21If you want to build hwclock, just cd to the source directory and invoke
22make with no parameters.
23
24hwclock calls option processing routines in the libsshopt library,
25which is part of Sverre H. Huseby's "shhopt" package. You
26can find a more authoritative copy of this package on metalab
27(ftp://metalab.unc.edu/pub/Linux/libs/shhopt-X.Y).